Kaplan Nursing Entrance Practice Exam

What is the primary function of the mitochondria in a cell?

1. Photosynthesis

2. Aerobic respiration and energy supply

3. Protein synthesis

4. Storage of genetic material

The correct answer is: Aerobic respiration and energy supply

The primary function of mitochondria in a cell is to facilitate aerobic respiration and supply energy. Mitochondria are often referred to as the powerhouses of the cell because they play a crucial role in converting glucose and oxygen into adenosine triphosphate (ATP), the energy currency of the cell. This process occurs through a series of biochemical reactions known as the Krebs cycle and the electron transport chain, which take place within the mitochondria. In addition to energy production, mitochondria are involved in various other essential functions, including regulating metabolic pathways, generating heat, and playing a role in cell signaling and apoptosis (programmed cell death). However, their most recognized and fundamental role is in energy synthesis, making them vital for the proper functioning of both eukaryotic cells and the overall metabolism of organisms. The other options do not align with the primary functions of mitochondria: photosynthesis is conducted by chloroplasts in plant cells, protein synthesis occurs primarily on ribosomes, and genetic material is stored in the nucleus of the cell. Thus, the significant role of mitochondria in aerobic respiration and energy supply sets them apart as essential organelles in cellular biology.